1. Field of the Invention:
This invention relates to a method of joining two superimposed flat thin objects together, for example, two corrugated sheets of a resin.
2. Description of the Prior Art:
A known method of joining, for example, two superimposed sheets of a resin together employs metal staples which are driven through the sheets, and clinched at the protruding ends thereof. The use of the metal staples for joining the resin sheets, however, makes difficult or impossible the reuse of the resin sheets in a recyclable manner which calls for the removal of the staples. The metal staples are harder than the resin sheets, and therefore, likely to damage any other resin sheet that may contact the staples. Moreover, the metal staples are likely to get rusty with the passage of time.
Another known method is intended for joining together two superimposed sheets of a resin each having holes which are alignable with the holes of the other sheet. A pin of the same resin as the resin of the sheets is passed through each pair of aligned holes, and deformed by melting at its protruding end to secure the sheets together. This method is beneficial from a recycling standpoint, insofar as both the sheets and the pins are of the same kind of a resin. The necessity of making the holes for the pins is, however, a disadvantage from a productivity standpoint.